engine

A few weeks ago an incredible video of an engine exploding started making the rounds on Facebook. This particular engine was thankfully in a dyno room, rather than sitting a couple of feet away from a driver on a track. We’ve all seen engine carnage videos before, but this one stands out. This diesel engine literally rips itself apart, with the top half of the engine flipping and landing on one side of the room while the bottom half sits still spinning on the dyno frame.

Building performance engines is part science, part engineering, and part hacking. While F1 racing teams have millions of dollars of test and measurement equipment at their disposal, smaller shops have to operate on a much lower budget. In this case, the company makes their modifications, then tests things out in the dyno room. Usually, the tests work out fine. Sometimes though, things end spectacularly, as you can see with this diesel engine.

The engine in question belongs to Firepunk diesel, a racing team. It started life as a 6.7 liter Cummins diesel: the same engine you can find in Dodge Ram pickup trucks. This little engine wasn’t content to chug around town, though. The Firepunk team builds performance engines — drag racing and tractor pulling performance in this case. Little more than the engine block itself was original on this engine. Let’s take a deeper look.

The engine is based around a single piston and runs on compressed air. The reduced parts count is a result of using the propeller axle as a key component in the engine itself. There are flat surfaces on the engine end of the axle which allow it to act as a valve and control its own timing. [gzumwalt] notes that this particular engine was more of a thought experiment and might not actually produce enough thrust to run an airplane, but that it certainly will spark up some conversations among RC enthusiasts.

The build is also one of the first designs in what [gzumwalt] hopes will be a series of ever-improving engine designs. Perhaps he should join forces with this other air-powered design that we’ve just recently featured. Who else is working on air-powered planes? Who knew that this was a thing?

If you have a car parked outside as you are reading this, the overwhelming probability is that it has a reciprocating piston engine powered by either petrol(gasoline), or diesel fuel. A few of the more forward-looking among you may own a hybrid or even an electric car, and fewer still may have a piston engine car powered by LPG or methane, but that is likely to be the sum of the Hackaday reader motoring experience.

We have become used to understanding that perhaps the era of the petroleum-fueled piston engine will draw to a close and that in future decades we’ll be driving electric, or maybe hydrogen. But visions of the future do not always materialize as we expect them. For proof of that, we only need to cast our minds back to the 1950s. Motorists in the decade following the Second World War would have confidently predicted a future of driving cars powered by jet engines. For a while, as manufacturers produced a series of prototypes, it looked like a safe bet.

The Chrysler gas turbine car from [Bryan]’s article. CZmarlin [Public domain].Back in August, my colleague [Bryan] wrote a feature: “The Last Interesting Chrysler Had A Gas Turbine Engine“, in which he detailed the story of one of the more famous gas turbine cars. But the beautifully styled Chrysler was not the only gas turbine car making waves at the time, because meanwhile on the other side of the Atlantic a series of prototypes were taking the gas turbine in a slightly different direction.

Rover was a British carmaker that was known for making sensible and respectable saloon cars. They passed through a series of incarnations into the nationalized British Leyland empire, eventually passing into the hands of British Aerospace, then BMW, and finally a consortium of businessmen under whose ownership they met an ignominious end. If you have ever wondered why the BMW 1-series has such ungainly styling cues, you are looking at the vestiges of a Rover that never made it to the forecourt. The very successful Land Rover marque was originally a Rover product, but beyond that sector, they are not remembered as particularly exciting or technically advanced.

The Rover JET1 prototype. Allen Watkin [CC BY-SA 2.0].At the close of the Second World War though, Rover found themselves in an interesting position. One of their contributions to war production had been the gas turbine engines found in the first generation of British jet aircraft, and as part of their transition to peacetime production they began to investigate civilian applications for the technology. Thus the first ever gas turbine car was a Rover, the 1950 JET1. Bearing the staid and respectable styling of a 1950s bank manager’s transport rather than the space-age look you might expect of the first ever gas turbine car, it nonetheless became the first holder of the world speed record for a gas turbine powered car when in 1952 it achieved a speed of 152.691 MPH.

The JET1 was soon followed by a series of further jet-powered prototypes culminating in 1956’s T3 and 1961’s T4. Both of these were practical everyday cars, the T3, a sports coupé, and the T4, an executive saloon car whose styling would appear in the 1963 petrol-engined P6 model. There was also an experimental BMC truck fitted with the engine. The P6 executive car was produced until 1977, and all models were designed to have space for a future gas turbine option by having a very unusual front suspension layout with a pivot allowing the spring and damper to be placed longitudinally in the front wing.

The Rover-BRM racing car at Gaydon. David Merrett [CC BY 2.0].It was not only prototypes for production cars with gas turbines that came from Rover in the 1960s though, for in 1963 they put their gas turbine into a BRM racing chassis and entered it into the Le Mans 24 hour endurance race. It returned in the 1964 season fitted with a novel rotating ceramic honeycomb heat exchanger to improve its efficiency, racing for a final season in 1965.

The fate of the gas-turbine Rovers would follow that of their equivalent cars from other manufacturers including the Chrysler covered by [Bryan]. Technical difficulties were never fully overcome, the increasing cost of fuel made gas turbine cars uneconomic to run, and meanwhile by the 1960s the piston engine had improved immeasurably over what had been available when the JET1 had been produced. The Rover P6 never received its gas turbine, and the entire programme was abandoned. Today all the surviving cars are in museums, the JET1 prototype in the Science Museum in London, and the T3, T4, and Rover-BRM racing car at the Heritage Motor Centre at Gaydon. The truck survives in private hands, having been restored, and is a regular sight at summer time shows.

As a footnote to the Rover story, in response to the development of JET1 at the start of the 1950s, their rival and later British Leyland stablemate Austin developed their own gas turbine car. If international readers find Jet1’s styling a bit quaint compared to the American jet cars, it is positively space-age when compared to the stately home styling of the Sheerline limousine to which Austin fitted their gas turbine.

We were tipped off to an older video by [AgentJayZ] which demonstrates the proper use of lockwire also known as ‘safety wire.’ In high vibration operations like jet engines, street racers, machine guns, and that rickety old wheelchair you want to turn into a drift trike, a loose bolt can spell disaster. Nylon fails under heat and mechanical lock washers rely on friction which has its limits. Safety wire holds up under heat and resists loosening as long as the wire is intact.

Many of our readers will already be familiar with lockwire since it is hardly a cutting-edge technology — unless you are talking about the cut ends of lockwire which [AgentJayZ] warns will slice up your fingers if you aren’t mindful. Some of us Jacks-or-Jills-of-all-trades, with knowledge an inch deep and a mile wide, may not realize all there is to lockwire. In the first eight minutes, we’ll bet that you’ve gotten at least two inches deep into this subject.

[Editor’s Note: an inch is exactly 25.4 mm, if the previous metaphors get lost in translation. A mile is something like 2,933.333 Assyrian cubits. Way bigger than an inch, anyway.]

Now, those pesky loose bolts which cost us time and sighs have a clear solution. For the old-hands, you can brush up on lockwire by watching the rest of video after the break.

Thank you [Keith Olson] for the tip, and we’ll be keeping an eye on [AgentJayZ] who, to date, has published over 450 videos about jet engines.

Many of us made soda bottle rockets for science class. Some of us didn’t have that opportunity, and made them in the backyard because that’s what cool kids do. Water rockets work on the premise that if water is evacuated from one side of a container, the container will accelerate away from the evacuation point. Usually, this takes the form of a 2-liter bottle, a tire pump and some cardboard fins. [François Gissy] modified the design but not the principle for his water trike which reached 261 kph or 162mph.

Parts for the trike won’t be found in the average kitchen but many of them could be found in a motorcycle shop, except for the carbon fiber wrapped water tank. There wasn’t a throttle on this rocket, the clutch lever was modified to simply open the valve and let the rider hold on until the water ran out. The front brake seemed to be intact, thank goodness.

Powering vehicles in unconventional ways is always a treat to watch and [François Gissy]’s camera-studded trike is no exception. If you like your water rockets pointed skyward, check out this launch pad for STEM students and their water rockets. Of course, [Colin Furze] gets a shout-out for his jet-powered go-kart.

[Jennies Garage] found a used and abused inverter based generator in the clearance section of his local home improvement store. The generator had been returned on a warranty claim and was deemed uneconomical to fix. Originally $799, [Jennies Garage] picked it up for just $25. He documented his quest to get the device running with a trio of videos.

The generator had spark, but didn’t want to fire. The only obvious problem was the fact that the machine had been overfilled with oil. There was little or no compression, but that is not uncommon with modern small engines – many of them have a compression release mechanism which makes them easier to start.

With all the obvious problems eliminated, the only thing left to do was tear into the engine and figure out what was wrong. Sure enough, it was a compression issue. The overfull oil condition had forced engine oil up around the piston rings, causing them to stick, and snapping one of the rings. The cylinder bore was still in good shape though, so all the engine needed was a new set of rings.

That’s when the problems started. At first, the manufacturer couldn’t find the rings in their computer system. Then they found them but the rings would take two weeks to ship. [Jennies Garage] isn’t the patient type though. He looked up the piston manufacturer in China. They would be happy to ship him complete pistons – but the minimum order quantity was 5000. Then he started cross-referencing pistons from other engines and found a close match from a 1960’s era 90cc motorcycle. Ironically, it’s easier to obtain piston rings for an old motorcycle than it is to find them for a late model generator.

The Honda rings weren’t perfect – the two compression rings needed to be ground down about 1/2 a millimeter. The oil ring was a bit too thick, but thankfully the original oil ring was still in good shape.

Once the frankenpiston was assembled, it was time to put the repair to the test. [Jennies Garage] reassembled the generator, guessing at the torque specs he didn’t have. The surgery was a complete success. The generator ran perfectly, and lit up the night at the [Jennies Garage] cabin.

On today’s edition of ‘don’t try this at home,’ we’re transported to Russia to see [Igor Negoda]’s working jet bicycle.

This standard mountain bike comes equipped with a jet engine capable of 18kg of thrust, fixed to the frame under the seat with an adjustable bracket to change it’s angle as needed. A cell phone is zip-tied to the frame and acts as a speedometer — if it works, it’s not stupid — and an engine controller displays thrust, rpm and temperature. A LiPo battery is the engine’s power source with a separate, smaller battery for the electronics. The bike is virtually overgrown with wires and tubes that feed the engine, including an auxiliary fuel tank where a water bottle normally resides. Where’s the main fuel tank? In [Negoda]’s backpack, of course.

It certainly kicks up a mean dust cloud and makes a heck of a racket but the real question is: how fast does it go? From the looks of the smartphone, 72 km/h, 45 mph, or 18 rods to the hogshead.